Mapping and Evaluating Capricornia Cays Vegetation and Regional Ecosystems
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Prepared by: Biodiversity and Ecosystem Sciences, Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts. © The State of Queensland (Department of Science, Information Technology, Innovation and the Arts) 2012. Copyright inquiries should be addressed to <[email protected]> or the Department of Science, Information Technology, Innovation and the Arts, 111 George Street, Brisbane QLD 4000. Disclaimer This document has been prepared with all due diligence and care, based on the best available information at the time of publication. The department holds no responsibility for any errors or omissions within this document. Any decisions made by other parties based on this document are solely the responsibility of those parties. Information contained in this document is from a number of sources and, as such, does not necessarily represent government or departmental policy. If you need to access this document in a language other than English, please call the Translating and Interpreting Service (TIS National) on 131 450 and ask them to telephone Library Services on +61 7 3224 8412. This publication can be made available in an alternative format (e.g. large print or audiotape) on request for people with vision impairment; phone +61 7 3224 8412 or email <[email protected]>. ISBN: 978-1-920928-23-0 Citation Batianoff, G.N.1 2, Neldner, V.J.1, Naylor, G.C. 1 3 and Olds, J.A.4 (2012). Mapping and evaluating Capricornia Cays vegetation and regional ecosystems. Department of Science, Information Technology, Innovation and the Arts, Queensland Government. 80 pp. Front Cover: Design by Will Smith Cover plates: Top row: Coral reef edge on North West Island; sunset over the reef flat; and Pisonia grandis low closed-forest and herbland boundary on Lady Musgrave Island. Bottom row: White-capped noddys Anous minitus sunbaking: large Pisonia grandis tree: green turtle Chelonia mydas returning to sea on Lady Musgrave Island. All photos by VJ Neldner. 1 Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts, Brisbane Botanic Gardens Mt Coot-tha, Mt Coot-tha Road, Toowong QLD 4066 2 Deceased 3 Department of Environment and Heritage Protection, GPO Box 2454 Brisbane City QLD 4000 4 Ecological Assessment, Department of National Parks, Recreation, Sport and Racing, PO Box 697 Gympie, QLD 4570. TABLE OF CONTENTS Executive summary ...................................................................................................................... 6 PART A. BACKGROUND .............................................................................................................. 9 1 Introduction .......................................................................................................................... 9 1.1 Background to the project ................................................................................................ 9 1.2 Aims of the project ............................................................................................................ 9 1.3 History of past research ................................................................................................... 9 2 Physical environment ........................................................................................................ 11 2.1 Regional setting .............................................................................................................. 11 2.2 Island descriptions .......................................................................................................... 12 2.3 Land use history .............................................................................................................. 18 2.4 Climate ............................................................................................................................. 20 3 Methodology ...................................................................................................................... 27 3.1 Fieldwork ......................................................................................................................... 27 3.2 Flora ................................................................................................................................. 27 3.3 Vegetation ........................................................................................................................ 28 3.4 Soils ................................................................................................................................. 29 PART B. Results and discussion ............................................................................................... 30 4 Flora .................................................................................................................................... 30 4.1 Regional checklist ........................................................................................................... 30 4.2 New records ..................................................................................................................... 30 4.3 Patterns of species distribution ..................................................................................... 32 4.4 Character of flora ............................................................................................................ 35 4.5 Species richness ............................................................................................................. 36 4.6 Species of doubtful status .............................................................................................. 36 4.7 Comparison of island floras ........................................................................................... 37 4.8 Temporal patterns & human impacts ............................................................................. 39 5 Vegetation .......................................................................................................................... 40 5.1 Vegetation communities ................................................................................................. 40 5.2 Vegetation condition ....................................................................................................... 42 6 Soils properties .................................................................................................................. 44 6.1 Overview .......................................................................................................................... 44 6.2 Soil classification ............................................................................................................ 44 6.3 Chemical properties ........................................................................................................ 46 6.4 Pisonia dieback at Tryon Island ..................................................................................... 49 6.5 Natural glades within Pisonia stands ............................................................................ 51 6.6 Soil condition overview .................................................................................................. 53 PART C. Conservation management ......................................................................................... 55 7 Current threats to vegetation ............................................................................................ 55 7.1 Pulvinaria urbicola .......................................................................................................... 55 7.2 Climate variability ............................................................................................................ 55 3 7.3 Plant resilience and vegetation changes ....................................................................... 56 7.4 Exotic plant species ........................................................................................................ 56 Concluding overview .................................................................................................................. 59 ACKNOWLEDGEMENTS ............................................................................................................. 60 REFERENCES ............................................................................................................................. 60 APPENDICES .............................................................................................................................. 66 LIST OF TABLES Table 1-1. List of publications and reports for individual islands .................................................... 10 Table 2-1. Details of island features and known disturbance history for each Capricornia Cay ..... 19 Table 2-2. Climate averages for the Capricornia Cays, based on weather records from Lady Elliot and Heron Islands (source: BOM, 2008a). .................................................................................... 21 Table 2-3. Ambient temperature changes for each decade at Lady Elliot Island ........................... 22 Table 2-4. Seasonal proportion of rainfall at the Capricornia Cays, Willis Island and Lord Howe Island from 1940–2007 ................................................................................................................. 25 Table 2-5. Wind conditions at Heron Island, Lady Elliot Island, Willis Island and Lord Howe Island (Source: BOM, 2008) ...................................................................................................................